package com.shdanyan;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.Resource;
import org.springframework.http.HttpHeaders;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.servlet.mvc.support.RedirectAttributes;

import com.shdanyan.storage.StorageFileNotFoundException;
import com.shdanyan.storage.StorageService;

@Controller
public class FileUploadController {

    private final StorageService storageService;

    @Autowired
    public FileUploadController(StorageService storageService) {
        this.storageService = storageService;
    }

    /*
     * @GetMapping("/") public String listUploadedFiles(Model model) throws
     * IOException {
     * 
     * model.addAttribute("files", storageService .loadAll() .map(path ->
     * MvcUriComponentsBuilder .fromMethodName(FileUploadController.class,
     * "serveFile", path.getFileName().toString()) .build().toString())
     * .collect(Collectors.toList()));
     * 
     * return "uploadForm"; }
     */
    @GetMapping("/")
    public String index() {

        return "forward:index.html";
    }

    @GetMapping("/files/{filename:.+}")
    @ResponseBody
    public ResponseEntity<Resource> serveFile(@PathVariable String filename) {

        Resource file = storageService.loadAsResource(filename);
        return ResponseEntity
                .ok()
                .header(HttpHeaders.CONTENT_DISPOSITION,
                        "attachment; filename=\"" + file.getFilename() + "\"")
                .body(file);
    }

    @PostMapping("/")
    public String handleFileUpload(@RequestParam("file") MultipartFile file,
            RedirectAttributes redirectAttributes) {

        storageService.store(file);
        redirectAttributes.addFlashAttribute("message",
                "You successfully uploaded " + file.getOriginalFilename()
                        + "!");

        return "redirect:/";
    }

    @ExceptionHandler(StorageFileNotFoundException.class)
    public ResponseEntity<?> handleStorageFileNotFound(
            StorageFileNotFoundException exc) {
        return ResponseEntity.notFound().build();
    }

}
